| 摘要 |
The system includes a housing 5 having a liquid inlet 8 and outlet 6, filtering material 2, 3, 4 and a non- return valve 9 preventing reverse flow through the inlet, the valve may be gravity actuated and incorporate a flexible valve member. Several sets of filtering material 2, 3, 4 may be provided. The system may be used in aquarium and may be provided with suction means for attaching to the glass of an aquarium. |
